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No, it was stainless, and the gas was inside the tank, not inside a welding chamber. I was just trying to offer an alternative method to determine when all of the air is displaced. It seems so wasteful to use ten times the volume of your welding chamber. Try it, it surprising that air coming out of a pipe, and argon coming out of a pipe, make a different sound.

My only experience welding titanium was when I fixed a cracked muffler cap from a Yamaha Y450F. I removed the cap and cut a strip of it off from the part that goes inside the muffler body. I then had a piece of welding rod that was the same material that I welded. I then put the cap into a cast iron frying pan, and ran my argon from my TIG torch into the pan for what I guessed to be a long enough period. I then repaired the crack in the open pan, and everything was going well. Then right at the end of the weld, I bumped the pan and it fell on the floor. That part of the weld turned into white powder. The rest of the weld was a straw color.

The point is, it is my opinion that you don't have to be surgically sterile or be scientifically oxygen-free to weld titanium.

Hi Spotsineyes,
Yes I totally agree.
Those chamber manufacturers are the ones that suggest ten times per vol.
I actually wonder if you repair a Ti dirt bike header weather or not you need to purge the pipe at all.
Dirt bike pipes don't last long enough anyway.

Hi Spotsineyes,
Yes I totally agree.
Those chamber manufacturers are the ones that suggest ten times per vol.
I actually wonder if you repair a Ti dirt bike header weather or not you need to purge the pipe at all.
Dirt bike pipes don't last long enough anyway.

Ji

Yes, the purge on the pipe makes a difference even on a dirtbike. In fact, more so, simply because of the abuse factor. For the OP, what I do when welding pipes, whether it be headers for a truck, or a bike, is to cap the end with masking tape, and insert a purge line. On a 2 stroke pipe, a good thing to do is to tack it up in as many sections as you can, using a purge line. Once spotted together, then you can use masking tape over the seams to prevent gas loss. As pointed out earlier, cool welds, and not too long. Alternate to keep the pipe from tweaking as you weld it up. Tape up a seam you are not working at that time, and when you get close to the tape, peel it of, and clean with acetone lightly. Same process for SS, or Ti. If regular steel is crap, then i will purge it too to minimize my issues.

A motorcycle does not work like a car, and an ultra-low c/g, even if you could achieve such a thing, would not be at all desireable, as it is in a car. And not that it counts for much, but besides being prone to dragging, I thought the low-mounted factory pipes on my old '76 RD400C Yamaha looked dorky, so they had to go! (One of my 2011 resolutions is to learn how to post pix; but first I need to learn how to keep this beach from deleting my text ).

Yes, the purge on the pipe makes a difference even on a dirtbike. In fact, more so, simply because of the abuse factor. For the OP, what I do when welding pipes, whether it be headers for a truck, or a bike, is to cap the end with masking tape, and insert a purge line. On a 2 stroke pipe, a good thing to do is to tack it up in as many sections as you can, using a purge line. Once spotted together, then you can use masking tape over the seams to prevent gas loss. As pointed out earlier, cool welds, and not too long. Alternate to keep the pipe from tweaking as you weld it up. Tape up a seam you are not working at that time, and when you get close to the tape, peel it of, and clean with acetone lightly. Same process for SS, or Ti. If regular steel is crap, then i will purge it too to minimize my issues.

This is the way we purge Medical gas lines when were putting them in. Works good as gold. On a side note though, you wouldn't need to have a closed box full of purge gas to do it the other way, so long as the air where your welding is reasonably still and not windy. Guys working on live gas lines weld in trenches with a purge gas in the trench. Just think smaller like a box made to fit around the pipe. Same concept. If ya want to know if its full of purge gas, light a match and see where it dies out as ya lower it into the box.

Also, have you checked into Hydro Forming your pipes? The ones I have on my RD400 were done that way.